l1 = 'a'
l2 = 'c'
l3 = 't'
l4 = 'i'

letterlist = [l1, l2, l3, l4]

wordslist = []

for x in range(0, 4):
	wordslist.append(letterlist[x])
	for xx in range(0, 4):
		if x != xx:
			wordslist.append(letterlist[x] + letterlist[xx])
		for xxx in range(0, 4):
			if x != xx and x != xxx and xx !=xxx:
				wordslist.append(letterlist[x] + letterlist[xx] + letterlist[xxx])
			for xxxx in range(0, 4):
				if x != xx and x != xxx and xx !=xxx and x != xxxx and xx != xxxx and xxx != xxxx:
					wordslist.append(letterlist[x] + letterlist[xx] + letterlist[xxx] + letterlist[xxxx])
			
print wordslist
